from typing import List


# 课程
class Subject:
    def __init__(self) -> None:
        pass


# 学生
class Student:
    def __init__(self, subjects: List[Subject]) -> None:
        self.subjects = subjects


# 教师
class Instructor:
    def __init__(self, subjects: List[Subject]) -> None:
        self.subjects = subjects


# 系
class Department:
    def __init__(self, instructors: List[Instructor], subjects: List[Subject]) -> None:
        self.instructors = instructors
        self.subjects = subjects


# 学院
class School:
    def __init__(self, students: List[Student], departments: List[Department]):
        self.students = students
        self.departments = departments
